/Engine/Plugins/Runtime/AR/AppleAR/AppleARKitFaceSupport/Source/AppleARKitFaceSupport/Public/AppleARKitFaceMeshComponent.h
Returns the frame number that was last used to update this component
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintPure, Category="Components|ARFaceMesh") int32 GetLastUpdateFrameNumber() const